Staple



(No Model.)

H. R. ADAMS.

I STAPLE.

No. 262,635. Patented Aug. 15, 18 82..

UNITED STATES ATENT OFFICE.

HIRAM R. ADAMS, OF BOSTON, ASSIGNOR TO DANIEL W. GOOOH, TRUSTEE, OF MELROSE, MASSACHUSETTS.

STAPLE.

SPECIFICATION forming part of Letters Patent No. 262,635, dated August 15, 1882.

Application filed December 8,1881. (N model.)

To all whom it may concern:

Be it known that I, HIRAM R. ADAMS, of Boston, county of Suffolk, State of Massachusetts, have invented an Im provement in Shoulder-Threaded Staples, of which the following description,in connection with the accompanying drawing, is a specification.

This invention relates to a fastening-staple, and has for its object to produce a staple that can be readily driven into soft materialsuch as wood-and when so driven will offer a large resistance to being withdrawn.

The invention consists in providing both the legs of the staple with a series of annular projections, shown as continuous threads winding spirally around the said legs, the said projections being angular and inclined upward, their outline appearing like a series of ratchet-teeth inclining upward from the point to the bent 2o portion of the staple. These teeth or projections have a wedge-like action when entering the material, and force the particles aside, and are forcibly engaged by the said particles to resist the backward movement or withdrawal of the staple.

The drawing shows in side elevation a staple constructed in accordance with this invention, it consisting in this instance of a continuous piece of wire bent in U shape. The two legs or pointed portions of the staple are each provided with a series of angular projections, a, that surround and run spirally along the said legs. The said projections incline upward, so that their outline is similar to a series of ratchet-teeth, and the soft fibrous material in which 5 the said staple is driven will expand to fill the spaces between the said projections, acting thereon like a series of pawls to resist its withdrawal or movement in the direction of the arrow 2. In driving the staple into the material in the direction opposite the arrow 2 the said projections a have a wedge-like action upon the particles of the said material, forcing them aside, so that comparatively small resistance is offered to this inward movement 5 of the staple.

I claim As an improved article of manufacture, a staple provided with the series of spiral projections broadest at their upper ends, substantially as shown and described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

HIRAM R. ADAMS.

Witnesses:

J 03. P. LIVERMORE, W. .H. SresroN. 

